Water, water, everywhere is the term that was taught to us when we were in primary school. Magicians were to be called in school to entertain school children. Magician showed us an illusion item called water, water, everywhere. The magician carries out this item with a student, pinching water from any part of the body of the student. This was a very interesting and amusing experience for us at that time. We were not knowing the importance of water in our body. As we grew up, we came to know the significance of water in our body. We also understood the natural water cycle. Our body weight’s 65% weight is of water and the remaining 35% weight is of flesh and bones. It is surprising to us now.
WATER, WATER, EVERYWHERE
Water, water, everywhere is a true term. When we look at our surrounding we find water existing in everything. In the air, in trees, in our body, in rivers, in the pond, in lakes, under the earth, in clouds, on mountains, in oceans, in soils, in wells etc. This waterbody changes its place from one body to another due to the water cycle. There are certain natural processes that change the place of water. These processes are evaporation, transpiration, condensation, precipitation and percolation. These processes circulate the water on the earth to the atmosphere and back to earth. This is the never-ending process unless and until we disturb this with pollution and deforestation.
WATER CYCLE PROCESS
The water cycle is the exchange of energy that affects the climate. When water evaporates, it takes energy from the atmosphere and makes it cool. When water condenses, it releases energy into the atmosphere and makes it warm. Water cycle processes are briefly discussed below:
Evaporation is the process when the sun heats up water in rivers, lakes, and oceans. Water is turned into vapour and goes into the atmosphere.
This is the process in the plant and trees. Where plant and trees absorb water through their roots, from the soil. Water then moves to the leaves of the plant. Water evaporated into the air through leaves.
Condensation is the process when water vapour loses its heat to the surrounding atmosphere. Water Vapour changes back into water droplets. Many tiny droplets together form the clouds.
Precipitation is the process when a large number of water droplets are formed. Atmospheric air can not hold any amounts of water droplets. Clouds in the atmosphere becomes heavier, hence the waterfalls on the earth as rain or snow.
Percolation is the absorption of rainwater through the soil. It is happening due to gravity and capillary force.
Human activities that have altered the water cycle:
- Construction of dams
- Water extraction from the riverbed
- Agricultural farming
- Industrial development
Construction of dams:
The building of dams, providing us with a large reservoir for water storage. Large water reservoirs are, to use water for farming, water for electricity generation, water for industries and water for domestic use. However, the construction of dams creates a still water reservoir. This still water reservoir gets heated up in summer, it results in abnormal temperature rise in the local area. This causes a change in the water cycle.
Trees and forest play an important role in maintaining the water cycle. The process of transpiration is reduced in the area, where plant and trees are cut. Deforestation reduces water vapour discharge in the atmosphere, hence a reduction in rainfall.
Water extraction from the river bed:
Water extraction from river bed reduces the water table in the surrounding area. As the water table goes down, moisture reduces in the topsoil of the earth. It results in less water absorption by plant and trees. This reduces the less transpiration of water vapour in the atmosphere, hence reduced rainfall.
The water cycle gets affected when vegetation cover is reduced from the soil. When soil density is increased with machines, it reduces the amount of water draining into the soil. Hence run off of rainwater increases. This process increases soil erosion and irrigation need is raised.
Industrial development is increasing pollution in the atmosphere. Due to the pollution global warming is happening and climatic changes are taking place. This global warming, changing rainfall pattern and causing floods and drought in many countries of the world.
Urbanization reduces the plantation and tree area. This reduces the less water retention in the soil and a large amount of water runoff during the rainy season. Due to run off of rainwater soil erosion takes place. It reduces the transpiration of water vapour into the atmosphere by the trees, hence reduces rainfall.